LeOS-Genesis/external/badvpn/misc/balign.h

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2020-10-05 13:12:00 +02:00
/**
* @file balign.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* Integer alignment macros.
*/
#ifndef BADVPN_MISC_BALIGN_H
#define BADVPN_MISC_BALIGN_H
#include <stddef.h>
#include <stdint.h>
/**
* Checks if aligning x up to n would overflow.
*/
static int balign_up_overflows (size_t x, size_t n)
{
size_t r = x % n;
return (r && x > SIZE_MAX - (n - r));
}
/**
* Aligns x up to n.
*/
static size_t balign_up (size_t x, size_t n)
{
size_t r = x % n;
return (r ? x + (n - r) : x);
}
/**
* Aligns x down to n.
*/
static size_t balign_down (size_t x, size_t n)
{
return (x - (x % n));
}
/**
* Calculates the quotient of a and b, rounded up.
*/
static size_t bdivide_up (size_t a, size_t b)
{
size_t r = a % b;
return (r > 0 ? a / b + 1 : a / b);
}
#endif